The current handheld devices usually have multiple functions and usually access or transmit a lot of data via 3G or LTE wireless technology. Although the power requirements of these wireless networks are high, thin design is a trend for handheld devices, which constrains the battery capacity of the handheld devices. When a handheld device has low power, the usual solution is to connect the handheld device to a power source using a wired connection. The handheld device may be plugged into a power outlet using a charging adapter or may be plugged into a notebook computer or other electronic device with a larger battery capacity using a USB cable. However, if the user of the handheld device does not have access to a suitable charging adapter or USB cable, the user may not be able to charge the handheld device. In the event that the user does not have access to a suitable charging adapter or a USB cable, it would be beneficial for the user to be able to tap into the power stored in the electronic device having the larger battery capacity.